SPX +10 / -10 From 9:30 Open

//version=5
indicator("SPX +10 / -10 From 9:30 Open", overlay=true)

// Exchange Time (New York)
sess = input.session("0930-1600", "Regular Session (ET)")

// Detect session and 9:30 AM bar
inSession = time(timeframe.period, sess)

// Capture the 9:30 AM open
var float open930 = na

if inSession
// If this is the first bar of the session (9:30 AM)
if time(timeframe.period, sess)[1] == na
open930 := open
else
open930 := na

// Calculate movement from 9:30 AM open
up10 = close >= open930 + 10
dn10 = close <= open930 - 10

// Plot reference lines
plot(open930, "9:30 AM Open", color=color.orange)
plot(open930 + 10, "+10 Level", color=color.green)
plot(open930 - 10, "-10 Level", color=color.red)

// Alert conditions
alertcondition(up10, title="SPX Up +10", message="SPX moved UP +10 from the 9:30 AM open")
alertcondition(dn10, title="SPX Down -10", message="SPX moved DOWN -10 from the 9:30 AM open")

// Plot signals on chart
plotshape(up10, title="+10 Hit", style=shape.labelup, color=color.green, text="+10", location=location.belowbar, size=size.tiny)
plotshape(dn10, title="-10 Hit", style=shape.labeldown, color=color.red, text="-10", location=location.abovebar, size=size.tiny)